/Engine/Plugins/Online/OnlineSubsystem/Source/Public/Interfaces/OnlineSessionInterface.h
Delegate fired when a player has left a session
typedef TMulticastDelegate_ThreeParams< void, [FName](API\Runtime\Core\UObject\FName), const [FUniqueNetId](API\Runtime\CoreOnline\Online\FUniqueNetId) &, [EOnSessionParticipantLeftReason](API\Plugins\OnlineSubsystem\Interfaces\EOnSessionParticipantLeftReason) > FOnSessionParticipantLeft